Giant Woodwasp

Urocerus gigas (Linnaeus)

Rune Axelsson
Terry Thormin

Hosts:

The giant woodwasp infests are variety of conifers including species of Abies, Cedrus, Chamaecyparis, Larix, Picea, Pinus, and Pseudotsuga. . In Argentina and Chile, where it has been introduced, it attacks Monterrey pine, Pinus radiata.

Adults are strong fliers, capable of covering several km in search of suitable host material. Moreover, larvae and pupae could easily be transported via international trade in unprocessed logs, wooden crating, pallets or dunnage. This insect has a high reproductive potential and broad host range. Conifers tend to have more or less continuous distributions in North America, allowing for rapid spread. Because North America has a complex of conifer infesting Siricidae that are similar in appearance, infestations could go undetected until significant damage occurs. Introduction of European or Asian subspecies, which may be vectors of fungi not present in North America, could, however, become tree killing pests as is case with the introduction of European woodwasp, Sirex noctilio, in several countries in the southern hemisphere.